The idea is to use a 4017 to generate sequenced pulses which gate four oscillators built from 4093 chips... according to the link above, the 4093 quad NAND gate can be gated by an external pulse when the voltage is high on one of it's inputs.

So, the idea is to set up the 4017 decade counter (with some osc as it's clock, maybe one of the four from the 4093?), with the counter outputs routed to separate inputs on the 4093. Each of the gates on the 4093 would be set up as an audio oscillator, with a pot to adjust pitch. When the counter hit the appropriate osc, it would turn on, and then off at the next pulse as the next osc was triggered?

Would that work? Do I need anything to keep the stepped outputs from the 4017 high while it is their "turn"?

Also, one additional thing I was wondering, does the 4017 automatically return to 0 when it has counted to 9, or do you need to set a reset to make it go back?

Much noise fun can be had from the chained 4093s you linked. Also try swapping the resistor and the capacitor on one of more of the 4093s. Also throw an XOR in instead of the NAND. But, you seem to be after musical notes more than noise, so...

You can hook four outputs of a 4017 to gate each of four NAND oscillators. The 4017 datasheet shows the pattern of those outputs. Each oscillator will play its own note. To mix: Feed each NAND oscilator output through an 100K resistor and tie the other end of those resistors together and feed that into your audio output circuit.

However, you will want a separate oscillator feeding the 4017 clock input, or else your four notes will play so fast they blend into noise--which might be good, too.

The 4017 resets automatically after the tenth step.
If you want a shorter sequence you can connect the output of the step AFTER the last step you want to the reset pin. The first step is called zero, so for instance for a 4 step sequence connect output 4 to reset.

It's not exactly what you are talking about, it has no internal sound source, but rather a CV/Gate out. Still, there are some parts of you might find interesting. Also a Google search for "Cascading 4017" will give you some schematics on linking several 4017 together for longer sequences.

cheers_________________Never confuse beauty with the things that put your mind at ease.

Cool idea!
If you wanted to you could use three of the 4093 gates to create a triad chord, and then use the fourth to be the clock for the 4017 (a much slower oscillator) and have a gated triggerable arppregio.

Ooh I like it, will try it when I get home.

EDIT
If you didn't want the looping there's probably a way to make the 4017's clock to stop after one loop, would take some more ICs though, hehe.

I tried a four step arppregio tonight using your idea and it worked pretty well. Each step stays high until the next step. If you don't reset it right at step 5, instead step 8 or so, you'll get a pause between each arpreggio.

At first it didn't make any sound because I just ran all of the outputs to one line of the breadboard and tapped that line to my amp. It works much better to run each of the outputs through their own resistor and then have all the points meet up for the output.

Still thinking about how to get it to stop after doing the sequence once., just out of curiosity.

Works pretty much just like expected. What I didn't realize though was that the gate input on the 4093 oscillators have to be grounded if they are not hooked up to a gate or they just run wild. Good to know.

It's just on the breadboard right now. No clips yet, but just imagine the old toy "simon". Sounds pretty much like that

I want to build this thing into a box for sure. I am thinking two 4093s to make seven audio oscillators and a clock. Pitch for each osc, and step switches for each osc (this would also allow sequencing of chords).

What will take some planning is figuring out how to subdue feature runaway syndrome...

I want to make this as easy/accessible to use as possible, but also least amount of toggle switches ($$$). I am thinking actually of making my own simple slide switches or something like that.

I might want to be able to have variable sequence length - maybe resets for 6,7,8,9,10 steps?. I shouldn't think about it too much beyond that... I will never stop adding features.

About the melody gen:
The 4017 is dividing the signal to change the notes of its audio rate clock. The clock of the 4017 is the base note that will be divided so it has to be audible.

The way to make 4017 change notes is by sending the different outputs to the reset pin, and to hear the result listen to the first output (pin 3.) Or even the next one since it isn't connected to anything.

The 4051 lets you select which of the 4017 outputs gets sent to the reset to change the notes. So 8 of the 4017 outputs get sent into the 4051 and the selected one comes out of pin 3.

The way to select which division you're going to do is to apply logic to the A, B, and C pins on the 4051. Usually that's some collection of slower clocks.

About the melody gen:
The 4017 is dividing the signal to change the notes of its audio rate clock. The clock of the 4017 is the base note that will be divided so it has to be audible.

The way to make 4017 change notes is by sending the different outputs to the reset pin, and to hear the result listen to the first output (pin 3.) Or even the next one since it isn't connected to anything.

The 4051 lets you select which of the 4017 outputs gets sent to the reset to change the notes. So 8 of the 4017 outputs get sent into the 4051 and the selected one comes out of pin 3.

The way to select which division you're going to do is to apply logic to the A, B, and C pins on the 4051. Usually that's some collection of slower clocks.

Cool stuff.

Thanks, I think I pretty much understand that...

So the 4051 is acting like a logic controlled multi-pole switch to mathematically (according to it's logic inputs) chose reset points (and therefore oscillation frequency) on the 4017? What are the parameters of the logic input on the 4051 - ie: how does it chose which input to send to output (to the reset)?

Just to play around, you could hear the "notes" the 4017 would play by having switches set up to activate the different reset points, right? A clock at high frequency driving the 4017 and then the output pins mixed to an audio output and also fed through switches back into the reset input?

Now I am wishing I would have bought a 4051 in my list of cmos 4000 series... well... enough to deal with just getting this thing together... want to use it for a show in 2 weeks.

So the 4051 is acting like a logic controlled multi-pole switch to mathematically (according to it's logic inputs) chose reset points (and therefore oscillation frequency) on the 4017? What are the parameters of the logic input on the 4051 - ie: how does it chose which input to send to output (to the reset)

There are 8 possible combinations of Hi and LOW at the ABC inputs, each coding a binary number. Three bits can count from 0 upto 7. This binary number is used to select one of the in/outputs.

Top Top wrote:

Just to play around, you could hear the "notes" the 4017 would play by having switches set up to activate the different reset points, right? A clock at high frequency driving the 4017 and then the output pins mixed to an audio output and also fed through switches back into the reset input?

Mixing? Nooo!
The 4017 Reset needs just one single signal, not a mix. For quick testing you needn't use switches, just a wire from a 4017 out of choise to the reset pin should do before you add the 4051. Also the Melody Generator uses just one output , pin 3 (or pin2) from the 4017.

Mixing? Nooo!
The 4017 Reset needs just one single signal, not a mix. For quick testing you needn't use switches, just a wire from a 4017 out of choise to the reset pin should do before you add the 4051. Also the Melody Generator uses just one output , pin 3 (or pin2) from the 4017.

Ah, what I meant was mixing for the audio part - thinking you would need to take the outputs separately - but now I understand, by taking the output from "0," you could get any of the divided frequencies of the variable resets.

As for switches, I meant only that it would make it easy to quickly test/hear the different reset pin frequencies. You could also just poke a wire around on the breadboard to achieve the same thing I suppose.

TopTop: Of cause I knew you'd figure it out, or maybe had some other circuits in your head that confused your post. The main reason for my last post is to clarify it some more for those that stumble upon this subject through a Forum search or Google.

8 oscs on the two 4093's - one acting as a clock for the 4017, the other 7 as audio oscilators - set up with .47uF caps and 100K pots - gets a pretty good range from bass sounds up to supersonic. I may add a resistor in series with the pots to get a little bit lower bass and take out the section of the pot that is supersonic (last couple % of the pot)

4069 is running a filter and a LFO.

I need to build this thing quickly because I am already starting to think of adding another 4093 to get 4 more oscillators...

Here's from two nights ago before I got the LFO going - and with just 4 oscillators going and resetting after 4 steps (breadboard is getting too crowded to put all of them on there).

The main thing that is still a mystery is how to set up the front panel to be able to have any step trigger any of the 7 oscillators. I am devising different ideas for making my own multi-pole, multi-throw switches. Patch cords are too slow/putzy (and jacks are too expensive), switches are too expensive and not versatile enough - I want to be able to trigger anywhere from 0 to 3 oscillators on any of the steps... any creative DIY switching ideas you may have are welcome. I am willing to fabricate simple parts... maybe I can make something out of those aluminum strips you can get from the hardware store.

This stuff is probably boring to you guys as it is actually pretty simple and straightforward... I wish I had known about these little cmos synths years ago though. I was into synth DIY when I was younger but ultimately got tired of it as much of it was too expensive, using too obscure of parts, too much calibration, etc...

You cannot post new topics in this forumYou cannot reply to topics in this forumYou cannot edit your posts in this forumYou cannot delete your posts in this forumYou cannot vote in polls in this forumYou cannot attach files in this forumYou can download files in this forum

Please support our site. If you click through and buy from our affiliate partners, we earn a small commission.